Lock-stitch sewing-machine



0. L. LAWSON. I LOOK STITCH SEWING MACHINE.

APPLICATION FILED MAY 29, 1914. P

Patented A11 10, 1916.

2 sHEETs-sHEET 1.

R m MK V m W I TNESSES:

0. L. LAWSON.

LOCK STITCH SEWING MACHINE.

APPLICATION FILED MAY 29, 1914.

1 1 9&5 1 Q. Patented Aug. 15, 1916.

2 SHEETS-SHEET 2.

WITNESSES: IN VEN TOR.

U SA. ATE If OSCAR L. LAWSON, OF LYNN, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO CARL ANDERSON, OF LOWELL, MASSACHUSETTS.

LOCK-STITCH SEWING-MACHINE.

Specification of Letters Patent.

Patented Aug. 15, 1916.

To all whom it may concern: 1

Be it known that I, OsoAn L. LAWSON, of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Lock-Stitch Sewing-li lachines, of which the following is a specification.

This invention relates to sewing machines for leather work and has particular reference to machines for sewing shoes.

My improvements are designed with special reference to providing a sewing machine which will be of low cost, and effectivefor the use of cobblers as well as for the general purposes to which leather sewing machines are put.

The particular object of my invention is to provide an improved presser foot mechanism.

In the drawings 1 have shown also an 1mproved mechanism for laying the thread in the hook of the needle, an improved spreader to open the loop to permit the hook of the shuttle to engage the loop and an improved thread lock and measuring mechanism, but I have not described said devices in detail in this specification because they form the subject matter of divisional applications as follows: stitch forming mechanism for sewing machines, filed March 25, 1915, Serial No. 17,046; loop spreader for sewing machines filed March 25, 1915, Serial No. 17,047; thread lock and measuring mechanism for sewing machines, filed April 22, 1915, Serial No. 23,220.

The invention will be fully understood from the following description when taken in connection with the accompanying drawings and the novel features thereof will be clearly pointed out in the claims at the close of the specification. Of the accompanying drawings: Figure 1 is a side elevation, partly broken out, of a machine embodying my improvements. Fig. 2 is a front elevation of the same, parts being omitted to avoid confusion. Fig. 3 is a detail side elevation of some of the mechanism shown in Fig. 1. Fig. 4 is a detail rear elevation, looking from the left of Fig. 3.

Similar reference characters indicate the same or similar parts in all of the views.

A suitable frame indicated at 20 has bearings for a main or driving shaft 21 one end of which is provided with a crank 22 (Figs.

1 and 2) to which is pivotally connected the lower end of an arm 23 the upper end of which is formed or provided with a rack 24 engaging a pinion 25 secured to a shaft 26 mounted in the shuttle housing 27 The shuttle is conventionally illustrated at 28. The upper end of the arm 23 is guided in a bracket 29 which is mounted to oscillate on shaft 26 to permit the arm 23 and the rack 24 to assume different angles of inclination as the crank revolves, without binding in said guide.

The work support 30, needle 31, and awl 32 are or may be of any well-known construction. It is to be understood, of course, that the machine is of the type known as awl-feed. That is, by suitable mechanism not necessary to describe or illustrate in detail, the awl passes through a slot in the work support and is shifted when in upper position so as to feed the work along. The oscillating carrier or needle segment 33 and the needle guide 34 are or may be of any well-known construction, the needle, of course, being of the hook type shown in Fig. 1.

The presser foot 35 is carried by an arm pivotally supported by the frame at 36 (Figs. 1 and 3). The shaft 21 (Figs. 1 and 2) is formed with a crank 37 to which is connected the lower end of a link 38 the upper end of which is pivoted at 39 to the needle segment 33. Said needle segment has a cam groove 40 the greater length of which is concentric with the aXis of rotation of said segment, the upper end of the slot being abruptly curved inwardly. A roll 41 riding in slot 40 is carried by an arm 42 of a block or bracket 43 (Fig. 3) which is rotatably mounted upon a disk 44, which disk is itself rotatably mounted as presently described. Between the periphery of the disk 44 and the inner surface of the opening or the bearing of the block 43 on said disk are twoclutch balls 45, located on opposite sides of the center of oscillation, and mounted in channels in the block 43 which channels are tangential to the periphery of the disk 44. Mounted in the channels are pins 46, the ends of the pins projecting from the rear edge of the block 43. Springs 68 indicated by dotted lines in Fig. 3, bearing against the sides of the balls opposite the pins 46 normally hold the balls in clutching positions. Since the two balls are opposite each other and both can only be released by thrusting pins v46 in, the block or bracket 43 is normally locked to the disk 44, but may be released therefrom by pushing the pins 46, the inner ends of the pins contacting with the balls so that when the pins are thrust in, the balls will both be released from clutching engagement. The means for automatically releasing the cultch balls at the proper times will be described hereinafter. The disk 44 is rotatively mounted on a stud 47 projecting from the frame, of the machine. An arm 48 projecting upwardly from the disk 44 is provided with a cam slot 49 which is eccentric to the axis of oscillation of said disk. A roll 50 carried by the rear arm 51 of the presser-foot engages the cam slot 49. A spring 52 (see dotted lines in Fig. l) connects a pin or hook 53 of the arm 48 and a fixed pin 54, said spring having a tendency to normally hold the arm 48 in the position indicated in Fig. 1, with the roll 50 in the upper end of the cam slot 49. It. will now be understood that whenever anything occurs to shift the disk 44 and its arm 48 in the direction of the arrow in Fig. l, the cam slot 49 will act on the roll 50 to lower the arm 51 and raise the presser-foot 35. This operation will be referred to more fully hereinafter.

To release the clutch balls, I provide an arm 55 pivoted at 56 and extending past the two pins 46 as shown in Fig. 3. The lower end of the arm 55 extends downwardly to a position to be acted upon at the proper time by a cam 57 carried by a disk 58 secured to the shaft 21. This cam is so located and operated as to timing in connection with the operation of sewing, that the cam 57 will act upon the arm 55 at the moment that the awl is in the work and has commenced to shift laterally to feed the work. This operation upon the arm 55 is so as to push both pins 46 inwardly and release both of the clutch balls 45 so that the block 43 and disk 44 will no longer be clutched tightly together, and the presserfoot can then yield, the pressure of the presser-foot upon the work being then only 1 such as caused by the spring 52.

In order to permit either one of the clutch balls 45 to be manually released, I provide mechanism which I will now describe: Mounted in the arm 55 (Figs. 3 and 4) in position to bear against the ends of the pins 46, are two plugs 59, the said plugs 59 having their inner ends formed as indicated by dotted lines in Fig. 3, and being loosely mounted in openings in the arm 55 so that H either plug 59 can be pushed in in a direction toward a pin 46, the formation and mounting of the plugs 59 being however, such that they cannot be shifted through the. openings in the other direction. In

t other words, either plug 59 can be shifted in the direction of its length and in a direction toward a pin 46, but cannot drop out or be pushed in the other direction through the openings in the arm To push either of the plugs 59 in, to act upon a pin 46, I provide a tilting lever 60 pivotally connected at 61 to a bracket projecting from the block 43. The upper end 62 and the lower end 63 of said lever 60 extend to positions to respectively actuate the upper plug 59 and the lower plug 59. A hand lever 64 pivotally connected at 65 to a link 66 which is pivoted at 67 to the block 43 has its lower end pivoted at 64" to the lever 60 above the pivot 61 of the latter. It will now be understood that by actuating the hand lever in one direction or the other it will oscillate the lever 60 so that its upper end 62 or its lower end 63 will act upon one of the plugs 59 to push in a pin 46 and release one or the other of the clutch balls 45, to permit the arm 48 to be oscillated in one direction but not in the other, as for instance when it is desired to hold the preslser-foot raised for the introduction of wor c.

In the operation of the machine, the timing is such that when the crank 37 is in lowest position so that the needle is raised, the inwardly curved upper end of the cam groove 40 (Fig. 1) acts on roll 41 to swing block 43 and causes the presser-foot to be lifted slightly during the feed operation of the awl. During the remainder of the stroke the concentric portion of the groove 40 holds the presser-foot against the work with a uniform and positive pressure. It will, therefore, be seen that the oscillating needle carrier 33 controls the height of the presserfoot during the formation of the stitch alternately pressing it against the work and releasing the work at the proper interval to permit the feed.

I claim 1. A sewing machine having a curved hook needle, an oscillating needle carrier, a movable presser foot and connections whereby the position of the needle carrier controls the height of the presser foot.

2. A sewing machine having a curved hook needle, an oscillating needle carrier having a cam, a movably mounted presser foot and means operated by said cam for raising and lowering the presser foot.

3. A sewing machine having a movably mounted presser foot, an oscillating needle carrier having a cam, and means controlled by said cam for raising and lowering the presser foot, said means including two clutch-connected members and means for re leasing the clutch connections.

4. A sewing machine having a movable presser foot, an oscillating needle carrier, two pivotally mounted arms having clutch connections between them, one of said arms being connected to the needle carrier to be actuated thereby when the needle is raised, connections between the other arm and the presser foot to raise and lower the latter, and means for automatically releasing the clutch connections.

5. A sewing machine having a movably mounted presser foot, an oscillating needle carrier having a cam, and means controlled by said cam for raising and lowering the presser foot, said means including two clutch-connected members and means for releasing the clutch connections, means being also provided for manually raising the presser foot and simultaneously releasing the clutch connections.

6. A sewing machine having a pivoted presser foot, two pivotally mounted arms having oppositely acting clutch balls between them, one of said arms having a cam for varying the height of the presser foot, a needle carrier, and connections between said carrier and the other arm for actuating the latter when the needle is raised.

7. A sewing machine having a pivoted presser foot, two pivotally mounted arms having oppositely acting clutch balls be tween them, one of said arms having a cam for varying the height of the presser foot, and an oscillating needle carrier having a cam for actuating the other arm.

8. A sewing machine having a pivoted presser foot, two pivotally mounted arms having oppositely acting clutch balls be tween them, one of said arms having a cam for varying the height of the presser foot, and an oscillating needle carrier having a cam for actuating the other arm, means being provided for manually raising the presser foot and simultaneously releasing one of said clutch balls.

9. A sewing machine having a pivotally mounted disk provided with an arm having a cam, a movable presser foot connected to be raised and lowered by said cam, a block mounted on said disk, a needle carrier having connections with said block to actuate it when the needle is raised, oppositely acting clutch balls between said block and disk, and means for shifting the clutch balls out of operative position.

10. A sewing machine having a pivotally mounted disk provided with an arm having a cam, a movable presser foot connected to be raised and lowered by said cam, a block mounted on said disk, a needle carrier having connections with said block to actuate it when the needle is raised, oppositely acting clutch balls between said block and disk, and means for manually shifting one or the other of said clutch balls out of operative position to permit the presser foot to be manually raised or lowered.

11. A sewing machine having a pivotally mounted disk provided with an arm having a cam, a spring connected thereto to cause said cam to depress the presser foot, a movable presser foot connected to be raised and lowered by said cam, a block mounted on said disk, a needle carrier having connections with said block to actuate it when the needle is raised, oppositely acting clutch balls between said block and disk, and means for shifting the clutch balls out of operative position.

12. A sewing machine having a pivotally mounted disk provided with an arm having a cam, a' movable presser foot connected to be raised and lowered by said cam, a block mounted on said disk, a needle carrier having connections with said block to actuate it when the needle is raised, oppositely acting clutch balls between said block and disk, pins mounted in the block for releasing the balls, an arm pivoted to the block and adapted to actuate the said pins, and means for automatically actuating said arm.

13. A sewing machine having a pivotally mounted disk provided with an arm having a cam, a movable presser foot connected to be raised and lowered by said cam, a block mounted on said disk, a needle carrier having connections with said block to actuate it when the needle is raised, oppositely acting clutch balls between said block and disk, pins mounted in the block for releasing the balls, an arm pivoted to the block and adapted to actuate the said pins, plugs mounted in said arm in alinement with said pins, a

hand lever connected with the arm of said disk, and means whereby movement of the hand lever in one direction will actuate one of said plugs and in the other direction will actuate the other plug.

In testimony whereof I have aflixed my signature, in presence of two witnesses.

OSCAR L. LAWSON. Witnesses A. W. HARRISON, A. F. RANDALL.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

